System Databases
SingleStore has several internal or "System" databases (views):
cluster
: Stores cluster-level metadata that is replicated to all nodes in the cluster. This includes information about nodes host/ports etc. and information about databases and database partitions). Cluster replicas (named something like:cluster_{uint64_t}
) are created during DR (disaster recovery) cluster-to-cluster replication.information.schema
: Read-only. A large set of system tables containing metadata about clusters and all the components within them.memsql
: Stores metadata local to a given node, including which local databases exist, which local users exist, etc.
Other than information.schema
, these databases are not intended for users. Some commands are not allowed for these databases. For example: ATTACH
/ DETACH DATABASE
, BACKUP DATABASE
, DROP DATABASE
, REPLICATE DATABASE
, REBALANCE PARTITIONS
, RESTORE REDUNDANCY
.